Watch National Geographic Specials Season 25 Episode 4 Online
Dogs have served humankind in more ways than any other animal. You'll see loyal canines at work as they search for buried victims of an earthquake disaster, assist the physically disabled, and pull sleds in the blizzard conditions of Alaska. Find out how dogs are trained to "act" on the Lassie television show, and meet dogs that served as messengers on the battlefields of WWII.
